Abstract: A method of making a bioprosthetic conduit, comprises the steps of: (a) taking a cylindrical mould, having circumferentially spaced protuberances which extend radially from the axis; (b) curving a layer of a biocompatible sheet material around the cylindrical mould, and joining the opposed edges of the layer together along a longitudinal axis, parallel to the axis of the mould to form a tubular layer; and (c) removing the tubular layer from the mould and turning it inside out to form a cylindrical conduit with sinuses, the conduit being fully fixed by a chemical means; after removal or while still on the mould.

Abstract: A stent for a cardiac valve comprises a metal base ring having metal legs projecting therefrom in a generally axial direction, each leg being flexible in such a manner that, when the stent has a valve installed therein and the valve is under pressure such as when operating in the heart, each respective leg can resiliently deform over substantially its whole axial length to take up strain in the valve without impairing its performance.